1. Field of the Invention
The invention pertains to heat exchangers for refrigeration circuits which condense refrigerant.
2. Description of the Related Art
Refrigeration circuits include a condensing coil usually consisting of conduits or tubes mechanically connected to metal fins whereby the tubes are cooled by air being forced over the fins and tubes, and such cooling of the tubes and heat exchanger condense gaseous refrigerant to a liquid state prior to the liquid being expanded for heat absorption purposes.
Conventional condensing heat exchangers include a header or manifold supplying the gaseous refrigerant to the coils, and the liquified refrigerant from the heat exchanger is piped to a separate external receiver reservoir prior to the liquified refrigerant being expanded.
As the receiver constitutes a separate component in the refrigeration circuit, its manufacture and associated plumbing and conduits add to the expense of the circuit.
The liquified refrigerant stored within the receiver may "flash back" to a gas before reaching the expansion device, depending on the temperature and pressure of the refrigerant with respect to its saturation point, and to prevent such "flash back" it is known to subcool the liquid refrigerant by a separate subcooling heat exchanger. Subcooling is well known in the refrigeration art as shown in U.S. Pat. Nos. 2,286,025 and 5,146,767.
The requirement to provide a separate subcooling heat exchanger, in combination with a separate refrigerant receiver, all adds to the expense of manufacturing the refrigeration circuit components, and further increases the bulk and size of the space necessary to accommodate the refrigeration circuit components.